Introduction to AWS S3 and its operations

Posted By : Pulkit Chadha | 16-Jun-2017

AWS

Introduction:
Amazon Simple Storage Service (Amazon S3) is one of the service to store and retrieve any amount of data from anywhere on the web.Customers can use AWS S3 as primary storage for their web applications.Storage pricing varies by region and class of storage.

Before, we proceed we need the following things:

AccessKeyId: '***********'

SecretAccessKey: '***********'

Bucket Name: 'TEST-BUCKET'

Region: '' // Region of Your S3 Bucket

Step 1: First, install AWS SDK package in your application using the command:

npm install aws - sdk

or

npm install aws - sdk --save //save to package.json

Step 2: Write the code given below:

var AWS = require('aws-sdk');
var fs = require('fs');

//Constants
var ACCESS_KEY_ID = '***********';
var SECRET_ACCESS_KEY = '***********';
var BUBKET_NAME = 'TEST-BUCKET';
var REGION = 'us-east-1';

//Initialize
AWS.config.update({
	accessKeyId: ACCESS_KEY_ID,
	secretAccessKey: SECRET_ACCESS_KEY,
	region: BUBKET_NAME,
	signatureVersion: "v4"
});


//Upload To AWS S3

var uploadToS3 = function (fileName, PathToFile, callback) {
	s3 = new AWS.S3({
		apiVersion: '2017-01-31'
	});
	fs.readFile(PathToFile, function (err, file_buffer) {
		var params = {
			Bucket: BUBKET_NAME,
			Key: '/Images/' + fileName, // If folder not exists,it is auto. created on S3 bucket.
			ContentDisposition: 'attachment',
			Body: file_buffer
		};
		s3.upload(params, function (err, data) {
			callback(err, data)
		});
	});
}


//Get file

var getFileFromBucket = function (fileName, callback) {
	var s3 = new AWS.S3();
	var params = {
		Bucket: configurationHolder.config.bucketname,
		Key: '/Images/' + fileName
	};
	s3.getObject(params, function (err, data) {
		if (err) {
			callback(err, null);
		} else {
			console.log("downloaded successfully", data.Body);
			callback(null, data.Body);
		}
	});
}

// List files  

var listFilesOnAWS = function (callback) {
	var s3 = new AWS.S3({
		apiVersion: '2017-01-31',
		params: {
			Bucket: BUBKET_NAME
		},
		region: REGION
	});

	var params = {
		Bucket: BUBKET_NAME
	}
	s3.listObject(params, function (err, success) {
		callback(err, success);
	});
}

// Delete files from AWS S3

var deleteFromAWS = function (FilePath, callback) {
	var s3 = new AWS.S3({
		apiVersion: '2017-01-31',
		params: {
			Bucket: BUBKET_NAME
		},
		region: REGION
	});

	var params = {
		Bucket: BUBKET_NAME,
		Key: FilePath // File path stored on S3
	}
	s3.deleteObject(params, function (err, success) {
		callback(err, success);
	});
}

        THANKS